The surface scattering of structural components in satellite optical communication systems will directly affect the transmission efficiency of signals. Therefore, based on the self-built bidirectional reflection distribution function (BRDF) measurement system, the surface properties of titanium alloy and aluminum alloy structural parts are measured in this paper. The influence of the structure surface roughness and incident angle on the BRDF distribution at the 1550 nm laser communication wavelength is analyzed. The BRDF model of the surface of the structural part is established, and the optimal model parameters are obtained by the simulated annealing algorithm. The experimental results show that the relative root mean square error between the modeling results and the measured results is better than 7.26%. The ABg model parameters fitted according to the measured data provides the necessary data parameters for the stray light tracing calculation and system design in practical engineering applications.